"She had been chasing him for years," the insider says of Hailey. "And she was a shoulder to cry on when things went bad with Selena."

Hailey last dated the Biebs from 2015 to 2016. That also happened to be right on the heels of his relationship with Selena.

The source reveals: "Selena thinks that the two of them will be over before wedding preparations even begin!"

If you need on a refresher on exactly which words Selena thinks that Justin used on her and then on Selena, here is what Justin said on Instagram when he finally confirmed his engagement.

"Hailey I am soooo in love with everything about you!" Justin gushed. "So committed to spending my life getting to know every single part of you loving you patiently and kindLY."

One can't help but wonder how many of these phrases he used on Selena.

"I promise to lead our family with honor and integrity," Justin wrote. "letting Jesus through his Holy Spirit guide us in everything we do and every decision we make."

That first bit, about leading the family, is weird. Whatever, he and Hailey go to the same church so maybe she's okay with that kind of 1950s language.

"My heart is COMPLETELY and FULLY YOURS," the Biebs affirmed. "And I will ALWAYS put you first!"

"You are the love of my life Hailey Baldwin," Justin said, though one wonders if he tried the same line on Selena. "And I wouldn’t want to spend it with anybody else. You make me so much better and we compliment eachother so well!!"

He definitely meant to write complement, in case you think that he's just saying that he and Hailey say nice things about each other.

Justin wrote that he "can’t wait for the best season of life yet!. It’s funny because now with you everything seems to make sense!"

That seems like another line that he could have easily used on Selena. We don't know for sure, though.

"'He who finds a wife finds a good thing and obtains FAVOR from the Lord!'" Justin quoted. "This is the year of favor!!!!"

It seemed to a lot of people that, when Jelena 2.0 (they dated way, way more times than twice) fizzled out, Justin just decided to try the exact same thing on another ex.

One might characterize Hailey as being the Biebs' runner-up, though that would be unfair to Hailey.

Maybe Justin did use a lot of the same language when wooing both exes.

Of course, maybe that's just how he talks.

But there's a line between using familiar phrases and taking someone on the same dates and expressing the same feelings as if they were interchangeable.

We sincerely hope that Justin recognizes that Hailey is her own person.